I was reading in a mag about this. They make a braket that when you cut out the old dash brase you mount in the new one and it will stop the movment. If you were just to put in the Master cylinder and not the brase then ya it will move.

See in this photo From Classicparts it has the brase on the back

http://www.classicparts.com/images/71-925B.JPG


1959 Chevy Apache 3100/ 283 TBI / 4L60E

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